Arrays of independent pneumatic actuators are usually bulky and complex. Indeed, either a complex system of valves (at least 2N for an N×N array) is necessary to define the air or liquid path through the system or each transducer has a dedicated pump driving it. Soft materials like silicones are commonly used, since they are easily deformable, which allows to obtain large amplitude of displacement. However, the pressure supply needs to be continuously turned on to hold the actuator in the “on” position; meaning that it is power consuming.
Large array of densely-packed micro-actuators are notably present in Braille, haptics, displays, adaptive optics, fiber switches and tunable antennas. In these applications, the actuators size ranges from 1 μm to 10 mm in the Cartesian x-y-z directions, with hundreds to millions actuators per complete device. In order to control the actuators individually, a simple addressing scheme, ideally compatible with standard electronics, is required. Furthermore, there is a need for an overall low power consumption; a requirement that can be fulfill either by implementing a latching system within the transducer or by using an ultra-low power technology for switching each actuator. Finally, the manufacturing process has to be simple, compact and reliable to design a robust large array of micro-actuators.
Therefore, in the field of arrays of actuators, substantially improved solutions are required to reduce power consumption and losses, improve density of the actuators, reduce complexity, and make the arrays portable, for various applications.